Recurrence patterns in pediatric intracranial ependymal neoplasm: a systematic imaging work-up

Area of Science:

• Neuro-oncology
• Radiology
• Pediatric Oncology

Background:

• Ependymal neoplasms (EPN) are classified by location and genetics.
• Understanding recurrence patterns is crucial for patient management.

Purpose of the Study:

• To analyze imaging patterns of local and distant recurrences in supratentorial (ST) and posterior fossa (PF) EPN.
• To compare recurrence characteristics between ST-EPN and PF-EPN.

Main Methods:

• Retrospective multicenter study of patients with recurrent EPN.
• Assessment and comparison of imaging characteristics for ST-EPN and PF-EPN.
• Evaluation of local recurrence, leptomeningeal dissemination, intraparenchymal lesions, and extraneural metastases.
• Comparison of MR-signal characteristics of recurrent tumors to primary tumors.

Main Results:

• 73 patients with recurrent EPN were analyzed (56 PF-EPN).
• Posterior fossa EPN predominantly recurred locally (29/56), while supratentorial EPN showed intracranial dissemination (9/17).
• Recurrent tumors exhibited altered imaging features (e.g., T2, T1, contrast enhancement) compared to primary tumors. Leptomeningeal dissemination patterns differed, with ST-EPN mainly intracranial and PF-EPN showing spinal spread.

Conclusions:

• Recurrence patterns in EPN differ significantly between supratentorial and posterior fossa locations.
• Imaging characteristics of recurrent EPN can differ from the primary tumor, impacting diagnosis and treatment planning.